一种基于频率细分的X射线脉冲星周期估计方法（英文）

发布时间：2018-01-13 03:21

本文关键词：一种基于频率细分的X射线脉冲星周期估计方法（英文）　出处：《Frontiers of Information Technology & Electronic Engineering》2015年10期 　论文类型：期刊论文

更多相关文章： 脉冲星导航 周期估计 频率细分 CLP

【摘要】：目的:针对现有脉冲星周期估计算法精度低的问题,研究一种利用短时观测数据进行高精度X射线脉冲星周期估计的算法,为促进实时高精度X射线脉冲星导航提供算法支撑。创新点:提出频率细分的方法,推导continuous Lomb periodogram(CLP),实现X射线脉冲星非等间隔到达光子序列在细分频率处的频域分析。该方法可以显著减少运算复杂度,同时提高频域分析的频率分辨率,进而提高脉冲星周期估计的精度。方法:首先,考虑到X射线脉冲星信号是非等间隔到达的光子序列,本文采用专门用于非等间隔数据处理的fast Lomb方法对一段短时观测的脉冲星实测数据进行频域分析,获得一个初始频率作为脉冲星旋转频率的初值。然后,在该初始频率附近以高的频率分辨率做频率细分,获取设定数量的高精度细分频率。最后,对该段短时观测的脉冲星数据在这些细分频率处做CLP分析。在CLP中,峰值位置所对应的频率即为估计出的具有较高精度的脉冲星旋转频率,由该频率就可以确定高精度的脉冲星旋转周期。实测数据分析表明:当观测数据小于135 s时,本文算法的周期估计精度比fast Lomb方法和FFT方法高1到3个数量级,且仅增加了一点计算复杂度。同时,相比于HEAsoft的周期估计方法(efsearch),本文算法具有精度高计算复杂度低的优势。结论:本文算法解决了fast Lomb方法在周期估计时精度受数据长度和观测时间限制的问题,显著提高了X射线脉冲星周期估计的精度并降低了计算复杂度。同时短时高精度的周期估计有助于提高TOA估计精度及X射线脉冲星导航中实时位置和速度的估计精度。本文算法还可以用于变星及其他天体的周期估计。
[Abstract]:Aim: to solve the problem of low accuracy of existing pulsar period estimation algorithms, a high precision X-ray pulsar period estimation algorithm based on short-time observation data is studied. In order to promote real-time high-precision X-ray pulsar navigation algorithm support. Innovation: proposed frequency subdivision method. The continuous Lomb is derived. The frequency domain analysis of non-equal-interval photon sequences of X-ray pulsars at subdivision frequencies is realized. This method can significantly reduce the computational complexity and improve the frequency resolution of frequency domain analysis. Then the accuracy of the period estimation of pulsars is improved. Methods: firstly, considering the photon sequence of non-equal-interval arrival of X-ray pulsars. In this paper, the fast Lomb method, which is specially used for the processing of non-equidistant data, is used to analyze the measured data of a short-time observed pulsar in frequency domain. An initial frequency is obtained as the initial value of the pulsar rotation frequency. Then, the frequency subdivision is done near the initial frequency with a high frequency resolution to obtain a set number of high-precision subdivision frequencies. Finally. The pulsar data observed in this section are analyzed by CLP at these subdivision frequencies. In CLP, the frequency corresponding to the peak position is the estimated pulsar rotation frequency with higher accuracy. The high precision pulsar rotation period can be determined by this frequency. The analysis of measured data shows that when the observed data is less than 135s. The accuracy of the algorithm is 1 to 3 orders of magnitude higher than that of the fast Lomb method and the FFT method, and the computational complexity is only a little higher than that of the fast Lomb method and the FFT method. Compared with the period estimation method of HEAsoft. The algorithm has the advantage of high precision and low computational complexity. Conclusion: the algorithm solves the problem that the accuracy of fast Lomb method is limited by the length of data and the time of observation in period estimation. The accuracy of the period estimation of X-ray pulsars is greatly improved and the computational complexity is reduced. At the same time, the short-time and high-precision period estimation is helpful to improve the accuracy of TOA estimation and the real-time position and velocity of X-ray pulsar navigation. The algorithm can also be used to estimate the period of variable stars and other celestial bodies.
【作者单位】： School
【基金】：Project supported by the National Basic Research Program(973)of China(No.2014CB340205) the National Natural Science Foundation of China(Nos.61301173 and 61473228) the Aerospaced TT&C Innovation Program of 704 Research Institute of China(No.201405B)
【分类号】：P128.4;V448.2
【正文快照】： 1 IntroductionPulsars are rapidly rotating neutron stars emit-ting stable and regular signals(Manchester and Taylor,1977;Lyne and Graham-Smith,2006).They havebeen observed in radio,visible,X-ray,and gamma-ray bands of the electromagnetic spectrum(Sheikh,

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